17 Nov 2014

17 Nov 14 - Pacific Blainville's Beaked Whales

After a grim day at sea, I was glad to wake up to find that we were close to Mangareva Island, where we joined the Braveheart a couple of weeks before. The plan for a final chumming session off Mangareva. This didn't produce much of note on the Seabird front: a few Murphy's Petrels, a lone Tropical Shearwater & a single Sooty Shearwater. Later as we got closer to Mangareva, there was a Masked Booby, a few Red-footed Boobies, a few White-capped Noddies & a few of White Terns.
Murphy's Petrel: There were a few of them around the Braveheart
However, we did have a pod of at least four Blainville's Beaked Whales. They made several passes close to the stern of the Braveheart over a fifteen minute period and we had some tail-slapping & breaching from them. I'm used to Beaked Whales totally ignoring boats so this was superb, albeit sometimes they were a bit too close for photography with a 400mm lens. Unless stated otherwise, none of the photos are cropped, so it shows how close they interacted with the stationary Braveheart. These photos show the main identification features which are a Beaked Whale with a small, spindle-shaped head, a small dorsal fin located two-thirds of the way back along the body, tapering tail flukes with no median notch in the tail. The beak is moderately long in adults, but stubbier in younger individuals. Blainville's Beaked Whales have a very distinctive arched back to the jaw line. It's not easy to see this jaw line in adult males as the tusks erupt from the jaw. They are a fairly non-descript grey-brown colouration, but can have round or oval white scars on adults & males can be heavily scarred. They can grow to 4.7 metres long. They have a wide range and can be found in all temperate & tropical seas throughout the world where the water depth is between two hundred and a thousand metres deep.
Blainville's Beaked Whale: Female & youngster. The closer individual has a short beak suggesting it is a youngster
Blainville's Beaked Whale: Youngster. A harsh crop of the first individual shows the dark jaw line which curves up in a very distinctive shape behind the beak
 
Blainville's Beaked Whale: Female. The back individual has a number of white spots indicating it is perhaps an adult female, but it doesn't show the bulky tusks of a male
Blainville's Beaked Whale: Male. This individual is more scarred & spotted & is a male given they tend to be the most heavily spotted & scarred
Blainville's Beaked Whale: Male. A close up of the male's head shows the tusks (the bulges at the waterline). It is a pity that the beak was already underwater
Blainville's Beaked Whale: Male. Another view of the last individual
Blainville's Beaked Whale: Male. A close up shows the dorsal fin colouration is more uniform on this individual
Blainville's Beaked Whale: This is a different individual
Blainville's Beaked Whale: A view of the back as it prepared to submerge
Blainville's Beaked Whale: A crop of the dorsal fin of the last individual shows it has a paler centre to it
Blainville's Beaked Whale
Blainville's Beaked Whale
Blainville's Beaked Whale: This individual finally disappears, albeit it wasn't going deep
Blainville's Beaked Whale: This crop shows a different individual with a dark centred dorsal fin & a single obvious pale spot in front of the dorsal fin
Blainville's Beaked Whale: This crop shows the fourth individual with a dark centred dorsal fin & more spotting in front of the dorsal fin
A few hours later we sailed into Mangareva harbour & the sea part of the trip was over. We had to present our passports to formally re-enter French Polynesia, despite having visited a couple of uninhabited French Polynesian islands. We had time to enjoy an ice cream & a wander around the small town.

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